DESCRIPTION OF NAOBRANCHIA DENTICIS N. SP (COPEPODA, SIPHONOSTOMATOIDA, LERNAEOPODIDAE) PARASITIC ON DENTEX HYPSELOSOMUS (TELEOSTEI, SPARIDAE) FROM JAPANESE WATERS, WITH A KEY TO THE SPECIES OF NAOBRANCHIA

摘要

The adult female of Naobranchia denticis n. sp. is described based on material collected from the gill filaments of the yellowback seabream Dentex hypselosomus caught in the southern Sea of Japan off the northern coast of Kyushu. Characteristic features of the new species include a cephalothorax three times as long as the trunk, a trunk as wide as long, egg-sacs situated posterolateral to the trunk, without extending to the bases of the maxillae anteriorly, slightly inclined toward each other posteriorly, with three pairs of reinforcement ribbons; caudal rami longer than abdomen and digitiform; head with lateral adhesive lobes and 12 hyaline papillae. The male has not been found. Our finding represents the first report of Naobranchia species from Japanese sparid hosts and the fourth report of this genus from the coastal waters of Japan. A key to the 21 species of Naobranchia is also included herein. Three species (N. bellones, N. pomolobi, and an unspecified species of Naobranchia from Hawaii) are not considered members of this genus because they lack the ribbon-like maxillae.